Bone saw



Nov. 7, 1939.

E. R. DAMATO 2.179.250

BONE SAW Filed March 31, 1937 2 Sheets-Sheet 1 INVENTOR. Z 7

BY I 40 p @4; L5 2; M

ATTORNEY.

Nov. 7, 1939. E. R. DAMATO 2.179.250

BONE SAW 2 sheets-sheet 2 Filed March 31, 1937 INVENTOR.

Emi/ci A? DAmafa ATTORNEY.

Patentecl Nov. 7, 1939 I I UNITED STATES PATENT Fries Emile R. DAmato, St. Louis; Mo., assignor to A. SJAlce C0,, St. Louis, Mo., a corporation of Missouri ApplicationMarch s1, 192,7; Serial No. 133,952 16 Claims. (cries- 317) This invention relates in general to surgical; Referring now in more detail and by reference instruments and, more particularly, to a cercharacters to thedrawings, the instrument comt'ain new and useful improvement in surgical, prisesa so-called body-portion A having prefinstruments of the type commonly, known as erably the contour in end and side elevation best bone saws, seen in Figures 1,2, 6, and '7, the body A having 5' My invention has for its chief objectthelpro: I somewhat the shape of a flattened pear, as it vision of a surgical saw which is uniquely balmay be said. As shown, the section or body A anced and constructed for efficientsmooth steady is generally, as at I, in the: form of a solid block forward cutting; under downwardly applied presr having opposite flat side faces a, a, with the 19 sure with the incision within the vision of, the block I bored, as at (1 o communication With operating surgeon and with the elimination of. a preferably integral tubular extension or shell bone-burning or smoking,, the tearing of 2,. which axially projects angularly outwardly adjacent tissue areas, the fouling of dressings from the block I, but in a direction parallel to surrounding the field, and anytendency to move its side faces a, a, the block I being arcuately along the bone or jump or bounce so prevalent enlarged upon opposite sides, as at (1 for par- 15.

with other bone saws of which I am aware and tial registration with the cylindrical wall of the so usually taxing the surgeons skill. I shell 2.

My invention has for a further; object the At the base of the bore a the block I is transprovision of a bone saw which may be completely versely cut-away to accommodate and seat a sterilized, which may readily be driven and consecond tubular member or so-called frame-sup- 20 trolled by means remote from, the operating port 3, which is welded or otherwise permanently field, which may beeasily quickly, and accuunited to, and forms substantially an integral rately adjusted to effect a plurality of parallel part of, the block I. As shown and for purposes variably spaced incisions, whichis durable and presently appearing, the member 3 is off censturdy in structure, which may be conveniently tered; as'it may be said, with respect to the manipulated, andwhich is highlyefficient in the block I, that is to say, a greater partthereof is performance of its intended functions. disposed upon one side of the block I than upon And with the above and other objects in view, the other, and interiorly of the block I, the meme my invention resides in the novel features of; her 3Iissuitab1y cut-away upon one side for com- 0 form, construction, arrangement, and combina munication withthe bore (1 tion of parts presently described and pointedout I At its stem or upper end, the block I is prefi th lai s, erably, integrally formed with an upstanding In the accompanying drawings (2 sheets), projection or pin 4, suitably fixed upon which Figure l is a perspective view of a bone Saw is,a preferably fluted or otherwise surface roughconstructed in accordance with and embodying ened hand-grip 5, the longitudinal axis of which 35 my presentinvention; Is in thesame plane as, and angularly disposed Figure 2 is a slightly-enlarged front elevational to, the axis of the shell 2. view of the saw; I Disposed transversely through the block I at Figure 3 is a slightly-enlarged fragmentary right angles to its side faces a, a, and in alignside elevational view of the saw; I I ment with the axis of the member 3, is an ap- Figures 4 and 5 are sectional views ofthe saw, erture 6; communicating with which, and extaken approximately along the lines 4-4 and. tending radially outwardly therefrom through 5-5, Figure 2, respectively; the block I in preferably parallel relation to the Figure 6 is a sectional view of the saw-taken shell 2, is an opening 7 internally threaded for approximately along the line 6--6, Figure 3; receiving a knob-ended or otherwise suitably 4 Figure 7 is a sectional View of the saw, taken headed set-screw 8, all for purposes presently approximately along the line 'I--'I,- Figure 6; V more fully appearing and as best seen in Figures Figure 8 is a fragmentary, elevational view ofv l and '7. the saw with one'of its rotary blades removedp The tubular member 3, at its shorter end.

5m Figure 9 is a fragmental sideelevational view: portion 1), is internally threaded for a short disof the saw, illustrating in detail the driving-,gear tance inwardly of its extremity and provided spindle; and with a transverse slot c, for purposes presently Figure 10 is a fragmental sectional view of, more fully appearing and as best seen in Figthe driving-gear spindle, taken approximately ures 6, 7, and 10;

along the line ill-I0, Figure 9. 1 p Atlits relatively longer end-portion b, the

member 3 is axially cut-away to provide a segmental opening 9, the member 3 at the outer extremity of its said end-portion b having a closure end-wall I0 centrally provided with an axially extended aperture all also for purposes presently appearing and as best seen in Figures 2, 3, and 6.

The shell 2 is internally threaded for a suitable distance inwardly of its outer end, as best seen in Figure 7, for threadedly receiving an end-portion of a second surface fiuted or otherwise roughened tubular hand-grip |2, preferably rigidly held in place and against accidental removal or displacement by means of a set-screw or the like |3 radially threaded through the wall of shell 2 and engaged at its inner end in a recess or socket i4 provided for the purpose in the hand-grip l2. Preferably provided on the shell 2 at the base of the hand-grip I2, is a suitable finger or hand-guard h, as best seen in Figures 3 and '1.

Mounted for rotation axially within the tubular hand-grip I2, is a shaft |5 provided at its one or outer extremity with a conventional form of split coupling |6 for detachable connection with a flexible drive shaft I1, which is, in turn, drivingly connected to any convenient prime mover, such as an electric motor, not shown, the shaft l5 axially extending forwardly through the shell 2 and partially into the member 3, and pinned or otherwise fixed on the inner extremity of the shaft I5, is a suitable bevel gear l8, as best seen in Figures 1 and '1.

Disposed axially through the member 3, having a bearing at its one end in the aperture H of said end-wall l0, and supported at its opposite end by a preferably integral fiat, disk-shaped plug 20 thread-seated in the opposite internally threaded end b of the member 3, is a suitable stub-shaft It, the plug or shell-closure 20 being secured against accidental removal or displacement by means of a set-screw or the like 2| inserted into a small threaded socket 2| formed partially in the wall of the member 3 and partially in the plug 20, as best seen in Figures 9 and 10.

Rotatably mounted upon the shaft l9 within the member 3, are two companion spur-toothed, bevel-ended barrel-gears 22, 23, arranged with their respective bevel-gear end-portions in opposed meshing engagement with, and on respectively opposite sides of, the drive-shaft bevelgear l8, as best seen in Figures 6 and 7, it being, of course, evident that, upon rotation of the drive-shaft l5, the gears 22, 23, will be rotated in relatively opposite directions by the gear l8.

B designates a fiat suitably elongated somewhat diamond-shaped gear-housing or so-called frame, which at one end portion, as best seen in Figures 1, 2, and 8, is disposed in partial marginal registration with, and by means of a setscrew or other suitable attaching means 24 secured fiatwise upon the face a of, the block I of section A, the housing B being provided with -a transverse aperture, as at 6, for co-axial registration with the aperture 6 of section A and being suitably chamfered upon its inner face for accommodating and fitting over the adjacent arcuate wall a of the shell 2.

As best seen in Figures 4, 5, and 8, the gearhousing or frame B comprises preferably three fiatwise registering plates 25, 26, 21, secured together in abutting relation by means of suitable pins 28 and screws 29. The intermediate or central plate 26 is transversely provided With three aligned, peripherally intersecting annular apertures 30, 3|, 32, as best seen in Figure 4. The outer plates 25, 21, are each provided with respective apertures 32, which register or are aligned with, and of the same diametrical dimension as, the aperture 32 for fitting over and tightly embracing the projecting end-portion b of the member 3, as best seen in Figures 4 and 8. The plates 25, 21, are further each provided with respective pairs of transversely aligned coaxial openings 33, 34, disposed concentrically with respect to the apertures 30, 3|, respectively, of the intermediate plate 26. Thus the housing or frame B provides enclosed chambers and shaftjournals for operatively accommodating and supporting shaft-equipped flat intermeshing spur gears 35, 36.

The shaft of the latter gear 36 is in the form of a tubular spindle 31, within which a bladeshaft 38 is removably secured, as by means of diametrically opposed longitudinal set-screws 39. The shaft 38 has a length to project at its inner end outwardly of the frame B to preferably integrally support a transverse concentric plate 38, upon which a saw-tooth disk or blade 40 is fiatwise fixed as by means of screws or the like 4|, all as best shown in Figures 4, 7, and 8.

As so mounted and disposed, the blade 40 is peripherally, as it may be said, in alignment or registration with the pressure grip 5; and, as will be seen by reference to Figure 4, the gear 35 is so positioned in the frame or housing B as to project through the slot 0 in the short projecting end b of the member 3 for meshing engagement with the barrel-gear 23. Thus it will be evident that, upon rotation of the gear 23, the gear 35 will be correspondingly rotated and, in turn, transmit rotative movement to the gear 36, which, again in turn, effects rotation of the blade 40, the blade 40 being accordingly rotated in the same direction as the barrel-gear 23.

Carrying for rotation a second and similar or companion cutting-disk or blade 40, is a second or likewise companion frame or gear-housing B, which is constructed in a manner substantially similar to that of the gear-housing or frame B. The second frame'B, however, is formed for slidable adjustment and removable disposition axially upon the relatively longer end-portion b of the housing or support 3 and, to such end, has an aperture 32' diametrically sized for snug embracing engagement with the support endportion b, the intermediate blade-actuating gear 35' of the frame B, which corresponds to the similar gear 35 of the frame or housing assembly B, peripherally extending upwardly into the aperture 32' for meshing engagement with the barrel-gear 22, which latter projects peripherally through the shell-opening 9. Further, the face e of the housing B is chamfered or cutaway diagonally from the aperture 32 to pro vide a recess 43 conformable to the arcuate wall a of the block I for permitting the housing B to normally fit closely flatwise against the opposite face a thereof.

Fixed at an end in, and extending at right angles laterally from, the face e of the gearhousing B, is a cylindrical slide rod 44 diametrically sized to fit snugly in and slide through the registering apertures 6 and 6 of the block I and the companion fixed gear-housing or frame B, the slide rod 44 being provided with a the rod 44 and consequently also the frame 3' may be releasably secured by means of the screw 8.

Since the barrel-gear 22 is appropriately toothed along its entire length and peripherally extends through the opening 9, it will be apparent that the intermediate gear 35' of the slidable gear housing 3 will be in intermeshed driving engagement at any such longitudinally adjusted position of the gear-housing B, and it will further be evident, since the two barrelgears 22, 23, are respectively rotated in opposite directions, that the blades 40, All, will correspondingly be rotarily actuated in opposite directions. I I

i It will'also be seen that, when the frame B is operatively disposed on the support 3, the frames B and B are disposed in parallel registering relation with the twin disk-blades fill, 4U, juxtaposed therebetween in also aligned or parallel relation and variably spaced as the particular bone sawing operation may requir In use, the instrument, after suitable sterilization, may be connected through the coupling it to the flexible shaft ll, the blades ll M, set to any desired spaced relation as described, and the motor or otherprime mover set in motion. The blades All, Ml,may then be applied to the bonetissue upon which the operation is being performed for the production of two parallel cuts or incisions preparatory to the'insertion of an artificial bone or metal restoration, as will be well understood.

By reason of the unique form and structure of the present instrument, the operating surgeon is enabled, while applying suitable manual pressure downwardly on the disks 40, Ml, through the aligning hand-grip 5, to manipulate the instrument forwardly by means of the second handgrip l2 and thereby efiect a smooth, steady forward cutting operation, the surgical field being in no respect interfered with, and the operating surgeon having at all times a clear and unobstructed vision of and into the incision. Further, 1; since the cutting-disks Ml, Ml, are substantially in a direct line with the hand-grips 5, i2, the surgeon will at all times have accurate control of the instrument, and, since also the two diskblades 43, an, rotate in opposite directions, any tendency of the instrument to jump out of the kerfs or cuts is: substantially wholly eliminated. Also, by reason of the positive driving connection established between the blades 40, 40', and the power source, the speed and force of rotation thereof may readily be very accurately and sharply gauged.

The instrument fulfills in every respect the objects stated, and if desired, the slidable frame or housing B may be entirely removed for singlecut or slotting operations by the remaining blade l'fl.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the saw may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is,

1. In a bone saw, in combination, a body-block, a pressure hand-grip disposed upon the block, a guiding hand-grip disposed upon the block in obliquely angular relation to, and having its longitudinal axis disposed in the same plane as the longitudinal axis of, the pressure hand-grip, a

disk-blade, and means engaged with the block and blade for supporting the blade for rotary actuation in peripheral alignment with, and substantially in the same plane as the axes of, said grips.

2. Ina bone saw, in combination, a body block, parallel frames disposed upon opposite sides of the block, a pair of separate endwise aligned shafts operatively mounted on the frames, a pair of disk-blades operatively mounted on the shafts for rotation in aligned juxtaposition, and means for rotarily actuating the blades.

3. In a bone saw, in combination, a body-block, parallel frames disposed upon opposite sides of the block, a pair of disk-blades operatively mounted on the frames for rotation in aligned juxtaposition, and means: for rotarily actuating the blades in relatively opposite directions.

4. In a bone saw, in combination, a body-block, parallel frames disposed upon opposite sides of the block, a hand-grip disposed on the block, a pair of parallel disk-blades operatively mounted for rotation in aligned juxtaposition on the frames and disposed peripherally substantially in line with the hand-grip, and means for rotarily actuating the blades in relatively opposite directions.

5. In a bone saw, in combination, a body-block, parallel frames disposed upon opposite sides of the block, a pair of hand-grips having respective portions endwise engaged with the block, the axes of the respective hand-grip portions being disposed at an oblique angle one to the other and lying in the same plane, a plurality of parallel disk-blades operatively mounted on the frames for rotation in aligned juxtaposition, the axes of the blades being disposed at right angles to the longitudinal axes of the hand-grip portions, and means for rotatively actuating the blades.

' 6. In a bone saw, in combination, a body-block, a first disk-blade, a shaft operatively mounted on the block for supporting the blade for rotary actuation in fixed relation to the block, a second disk-blade, and a second shaft mounted separately from and in endwise alignment with the first shaft for supporting the second blade for rotary actuation in aligned juxtaposition with, and in adjustably spaced relation to, the first blade.

'7. In a bone saw, in combination, a body-block, a first frame disposed upon a side of the block, a support projecting transversely from the other side of the block, a second frame mounted for slidable adjustment on the support, and diskblades mounted on said frames for rotation in aligned juxtaposition.

8. In a bone saw, in combination, a body-block, a first frame disposed upon a side of the block, a support projecting transversely from the other side of the block, a second frame mounted for slidable adjustment on the support, disk-blades mounted for rotation on said frames for rotation in aligned juxtaposition, and means for releas ably securing the second frame and its carried blade in adjusted position relatively to the first frame and its blade.

9. In a bone saw, in combination, a body-block, a first frame disposed upon a side of the block, a support projecting transversely from the other side of the block, a second frame mounted for slidable adjustment on the support, disk-blades mounted for rotation on said frames for rotation in aligned juxtaposition, and means for releasably securing the second frame and its carried blade in adjusted position relatively to the means including meshing gears in the block,

housing, and frames for rotarily actuating the blades.

11. In a bone saw, a chambered body-block, a tubular housing disposed transversely, and having communication with the chamber, of the block, a tubular extension projecting angularly from, and having communication with the chamber of, the block, frames disposed upon opposite sides of the block and having embracing engagement with opposite end-portions of the housing,

each of said frames being chambered for communication with the housing, shafts journaled for rotation in said frames, disk-blades fixed on said shafts, and means for rotarily actuating the blades, said means including meshing gears in the block, housing, and frames, and a driving shaft disposed longitudinally in said extension.

12. In a bone saw, a chambered body-block, a tubular housing disposed transversely, and having communication with the chamber, of the block, frames disposed upon opposite sides of the block in embracing engagement with opposite end-portions of the housing, each of said frames being chambered for communication with the housing, shafts journaled for rotation in said frames, disk-blades fixed on said shafts, and means including meshing gears in the block, housing, and frames for rotarily actuating the blades, one of said frames being shiftable on the housing relatively to the block for adjustably spacing the blades.

13. In a bone saw, a chambered body-block, a

tubular support disposed transversely, and hav ing communication with the chamber, of the block, frames disposed upon opposite sides of the block in embracing engagement with opposite end-portions of the support, each of said frames being chambered for communication with the support, shafts journaled for rotation in said frames, disk-blades fixed on said shafts, means including meshing gears in the block, support, and frames for rotarily actuating the blades, one of said frames being shiftable on the support relatively to the block for adjustably spacing the blades, and means for releasably securing said shiftable frame in adjusted position.

14. In a bone saw, in combination, a body-block, parallel frames disposed on the body-block, a disk-blade operatively mounted on each of the frames in aligned juxtaposition, one of said frames being arranged for shiftable movement laterally toward and away from the other frame for providing an uninterrupted free space between the blades, and means for rotarily actuating the blades.

15. In a bone saw, in combination, a bodyblock, a pressure hand-grip having a portion endwise engaged with the block, a guiding hand-grip also having a portion endwise engaged with the block and disposed in angular relation to, and having its longitudinal axis in the same plane as the longitudinal axis of, said pressure handgrip portion, a disk-blade, and means engaged with the blade and block for supporting the blade in peripheral aligning registration with, and substantially in the plane of, the axes of said hand-grip portions for rotary cutting application under pressure presented through the pressure hand-grip downwardly upon the block while the saw is being propelled forwardly by the guiding hand-grip.

16. In a bone saw, in combination, a bodyblock, a pair of disk-blades, and means engaged with the block for supporting the blades for rotary actuation in aligned juxtaposition, said means including endwise aligning shafts separate and spaced one from the other at opposed ends.

EMILE R. DAMATO. 

